Background - Acupuncture within pregnancy has frequently been investigated, often with finding this to be more effective than standard care. However, the adverse event severity, types and occurrence are unclear. Objective - To investigate the quality of reporting adverse events and to attempt to identify occurrence, type and severity of adverse events in acupuncture and non-acupuncture groups. Results - Overall quality of reporting of adverse events was poor, with information describing the adverse events often lacking in detail. A number of trends were noted: adverse events occurring within a treatment session was 3%-17% in the acupuncture groups and 4-25% in the non-acupuncture groups. The percentage of women affected by an adverse event was between 14%-17% in the acupuncture groups and 15-19% in non-acupuncture groups. Conclusions - Adverse event reporting within acupuncture trials is generally poor. The trends noted were that adverse events do occur, but would appear to be largely minor and comparable to non-acupuncture related interventions.